How to Remove a Radiator for Decorating and Refit It
How to take a radiator off the wall without draining the whole heating system, then refit it, refill it and get the pressure back up. Includes what to do when a valve won't shut off.
You can usually remove a radiator without draining the whole system. Turn the heating off and let it cool, close the control valve and the lockshield valve (counting the lockshield turns), then loosen one union nut over a tray and open the bleed valve to drain the radiator. Undo the second union, lift the radiator off its brackets and keep it upright. Refitting is the reverse, followed by bleeding and topping up the boiler pressure. It only works if both valves shut off fully.
Key Takeaways
- Close both valves first. The lockshield is under a plain cap and needs a spanner or lockshield key. Count the turns so you can reopen it by the same amount.
- A standard radiator holds more water than people expect. Have a tray, towels and a bucket ready before you loosen anything.
- Keep the radiator upright when you carry it, or the sludge left inside ends up on the carpet.
- If either valve lets water through when closed, stop and tighten the union again. You'll need a drain-down or a new valve.
- After refitting, bleed the radiator and check the boiler pressure. Sealed systems lose pressure when a radiator is drained and refilled.
To remove a radiator, turn the heating off, close both of its valves, drain the radiator into a tray through one union nut, then undo the other union and lift it off the brackets. You don't normally need to drain the whole central heating system, as long as both valves shut off fully. Refitting is the same in reverse, followed by bleeding the radiator and checking the boiler pressure. This guide walks through each step, what to do while the radiator is off the wall, and what to do when a valve won't hold.
Can you remove a radiator without draining the system?
Usually yes. Every radiator has two valves: a control valve (a thermostatic valve or a manual wheelhead) and a lockshield valve under a plain cap. With both closed, the radiator is isolated from the rest of the system, and only the water inside the radiator itself needs to come out.
It doesn't work when a valve is too old or scaled to shut off, which is common on radiators that haven't been touched for years. Thermostatic valves can also let a little water through even on their lowest setting. Some have a separate decorating cap for that. If you can't isolate it, you'll need to drain the system down, or at least the section, and our guide on how to drain a central heating system covers that.
What you need
- Two adjustable spanners, or a spanner and grips, one to hold the valve still while you turn the nut
- A radiator bleed key
- A shallow tray that fits under the valve, and a bucket to empty it into
- Plenty of old towels and a dust sheet
- Rags or plastic bags and tape to cover the valve tails
- A second pair of hands for lifting
How to remove a radiator
Turn the heating off
Switch the heating off and wait for the radiator to go cold. Hot system water can scald.
Close the control valve
Turn a wheelhead fully clockwise. On a thermostatic valve, turn it to the off or frost setting. If the TRV head doesn't shut it fully, some models take a manual cap in place of the head.
Close the lockshield
Take off its cap and turn the spindle clockwise with a spanner or lockshield key, counting the turns until it stops. Write the number down. Our guide to the lockshield valve explains why this setting matters.
Drain through one union
Lay towels down and put the tray under the lockshield end. Hold the valve body steady with one spanner and slowly loosen the union nut between the valve and the radiator with the other. Open the bleed valve at the top a little to let air in, so the water flows. Tighten the nut to stop the flow while you empty the tray, then carry on.
Undo the second union
When the flow stops, undo the union on the other side. Expect a little more water.
Lift it off
Lift the radiator straight up off its brackets, with a helper for anything but a small one. Tip it up to drain the last water from the open ends into the tray, then keep it upright or lay it on towels with the ends plugged.
Cover the valve tails
Wrap the open valve ends in rags or plastic bags and tape them. It keeps paint and dust out, and catches any drips.
While the radiator is off
- Leave the heating off, or at least keep an eye on the capped tails the first time it runs, particularly with a weeping valve.
- Don't paint the valves or tails. Paint on the spindles and nuts makes them hard to turn and to seal next time.
- Check the brackets. If you're filling or plastering behind them, mark their positions so the radiator goes back level.
- Consider a flush. If the water that came out was black and the radiator was cold at the bottom, it may be worth flushing it out with a hose outside before refitting. See signs your radiators need a power flush.
How to refit it
- Hang the radiator back on its brackets and line up both valve tails with the unions.
- Start both union nuts by hand, so they don't cross-thread, then tighten with the spanner while holding the valve body still.
- Close the bleed valve.
- Open the lockshield by the same number of turns you counted, then open the control valve fully.
- Bleed the radiator as it fills until water comes out of the bleed valve. Our radiator bleeding page has more detail.
- Check the boiler pressure. On a sealed system, top it up to the level shown on the boiler, typically 1 to 1.5 bar cold. See how to repressurise a boiler.
- Turn the heating on, check both unions for drips, and bleed again once it's hot.
If you're swapping in a new radiator, measure the pipe centres, the distance between the two valve connections, before you buy. If they don't match, the pipes need moving. Our radiator replacement guide covers sizing and costs.
Common problems
| Problem | Likely cause | What to do |
|---|---|---|
| Water keeps coming with valves closed | Valve not shutting off fully | Retighten and drain down, or replace the valve |
| Union nut weeping after refitting | Not tight or not seated squarely | Tighten a little at a time. Reseal if it persists |
| Radiator cold after refitting | Lockshield still shut or air trapped | Check the lockshield and bleed again |
| Other radiators now cold | Pressure dropped or air in the system | Top up the pressure and bleed |
| Lockshield spindle won't turn | Scaled or painted over | Don't force it. Call a plumber |
If the radiator won't heat properly once it's back on, see why a radiator won't heat up. If one leaks from a valve rather than a union, see our guide to a leaking radiator.
When to call a plumber
Call a plumber if the valves won't shut off, if a spindle is seized, if you're taking off several radiators and want the system drained and refilled properly, or if you're fitting a new radiator that needs the pipework altering. It's also worth getting help with large or heavy column radiators, which can pull brackets out of old plaster.
We take radiators off and refit them for decorators and homeowners, replace valves and fit new radiators across London. See our radiator repair and radiator replacement pages. Our labour is £95 an hour, the £60 call-out is waived when the job runs over 2 hours, and we confirm the price before any work starts.
Radiators to take off or put back?
Tell us how many and whether the valves turn. We'll confirm the price before starting.
📞 Call 020 7870 3200Or see our radiator repairs and pricing.
Frequently Asked Questions
Can you remove a radiator without draining the system?
Yes, in most cases. Close the control valve and the lockshield valve on that radiator, then drain just the radiator through one of the union nuts. It only works if both valves shut off completely. If water keeps coming, the system or that section needs draining, or a valve needs replacing.
How do I turn off the lockshield valve?
Pull or unscrew the plain plastic cap to reveal the spindle, then turn it clockwise with a small spanner or lockshield key until it stops. Count the turns, so you can open it by exactly the same amount when you refit the radiator and keep the system balanced.
Do I need to repressurise the boiler after removing a radiator?
On a sealed system, usually yes. Refilling the radiator and bleeding the air out drops the pressure. Top it up through the filling loop to the level shown on the boiler, typically 1 to 1.5 bar when cold. Open-vented systems top themselves up from the small tank in the loft.
Why is my radiator leaking after refitting it?
Most often a union nut isn't tight enough or isn't seated squarely. Dry it off and tighten it a little at a time. If it still weeps, the joint may need resealing or the valve replacing. A leak from the bleed valve means it isn't fully closed.
Can I fit a different radiator in the same place?
Only easily if the pipe centres, the distance between the two valve connections, are the same or very close. Otherwise the pipework needs altering. The new radiator also needs to give out enough heat for the room, so check its output rather than just its size.